Vacuum pan



C. E. ROGERS Feb. 11, 1930.

VACUUM PAN Filed June 13, 1925 m VENTOR. 7/0/6156 P0555QOOOOGOOOQQOGOOOQOOGOOOO QQO OOOOQOQQQOOQOOOOOOOGOOQGOOOGOOOOOOOOOGOOQOOGO OOOOOGGOOQOOOOQOQOOO O 0 A TTORNEY.

Patented Feb. 11, 1930 PATENT OFFICE CHARLES E. noenns, or nn'rnorr,MICHIGAN VACUUM PAN Application filed .Tune 13,

This invention relates to vacuum pans for condensation of fluidscontaining solids, for instance milk, and is a substitute for my formerapplication Serial No. 484,617, filed July The object of the inventionis to provide an apparatus of the character stated having an increasedefficiency over previous known apparatus for the same purpose in thatthe 1 output per unit of heat applied is increased and foaming ispractically eliminated. In the majority of previous known apparatus theusual vacuum pans for condensation of milk or the like have an upperportion of a reduced diameter and a condenser on the-exterior of thepan.

WVithin my improved vacuum pan and extending diametrically thereacrossat the top, I provide a condenser of comparativelynarrow width, thecondenser being provided with means arranged diametrically across thepan above the trough for discharging water in fine streams into thetrough. Vapor is permitted to rise upon both sides of the trough tocontact the streams of water.

A further feature of the inventionis also involved in the constructionof a pan of substantially uniform diameter to a point practically levelwith the point of discharge of the condensing water into the pan.

By the general construction statedthat is, the forming of the pan of thesame diam eter up to the point of entranceof condensing fiuidthe vaporspass from the apparatus more readily and the velocity of movement andpressure during evaporation is reduced. These various objects and theseveral novel features are hereinafter more fully described, and thepreferred form of construction of a vacuum pan embodying my invention isshown in the accompanying drawings in which- Fig. 1 is a verticalsection of my improved vacuum pan.

Fig. 4 is a section taken on line l l of Fig.

1925. Serial No. 36,856.

1 showing the arrangement of the apertures for discharge of the waterinto the pan.

The pan as shown consists of a cylindrical shell 1 which may, ifdesired, be formed of several flanged sections and provided with a topcover 2 and a bottom 3. The seams between the several sections of thecylinder and top and bottom members are necessarily made air tight. Amanhole of any approved type indicated at 4 is utilized near the upperend of the cylindrical member which is to be understood as beingprovided with the, usual peep glass. A thermometer of the usual type isalso provided as shown in dotted lines at 5 and the usual milk inlet asshown in dotted lines at 6 and the butter cup indicated by dotted linesat 7. In the lower part of the pan are positioned the heating coils 8which may be of any approved type and are here shown as being made up ofseparate sections indicated by the inlets 9, 10 and 11. As will beunderstood from Fig. 2 the outlets are at one side of the inlet coils,which outlets are indicated at 12 and an outlet for another coil at 13.However, as before stated, any type of heating coil may be used as maybe found desirable so far as this invention is concerned. A heating coilin sections as here shown is desirable permitting the device to beeconomically operated with different quantities of milk-that is, with asmall quantity of milk the lower coil only with the inlet 11 may beutilized, which coil is provided with anoutlet 14 extending through thebottom of the tank. If a greater quantity of milk is used the nextsucceeding coil may be heated etc., as will be readily understood.

Preferably, although not of necessity, the pan is provided with anupwardly curved hemi-spherical bottom portion 15. With heat applied tothe coils, the milk adjacent thereto is heated and an upward flowthereof is occasioned circularly about the center which is not so highlyheated. The cooler central space'provides for practically unrestricteddownward flow of cooler fluid with an upward current of the heated fluidin circular form. The upwardly extending hemispherical portion 15 tendsto cause this downward current to spread beneaththe lower heating coilsat the bottom of the ascending current.

Efiiciency is also increased by making the pan of the same diameterthroughout its height thereby avoiding necessity of increasing thevelocity of flow of vapor through the upper portion as with the formertypes in which the upper part was usually of reduced diameter. Thisarrangement also permits an increase in the size and structure of thecondenser which preferably consists of the U shaped trough 16 extendingdiametrically across the upper end of the pan as will be understood fromFigs. 1 and 3. This trough member is provided with an outlet 17 to whichthe usual pump is attached to reduce the pressure in the pan and theoutside wall of this trough is insulated as indicated at 16 by anypreferred type of heat insulating material, the purpose of which is toprevent condensation of the vapors coming in contact with the exteriorof the cold trough 16. A water inlet 18 is provided in the top of thepan and a chamber 19 is provided therebelow having a multiple series ofapertures 20 through which water is discharged into the trough 16 whichfalls thereinto in fine streams. The trough is spaced a distance belowthe water chamber 19 as will be observed more particularly in Fig. 3 andthe vapors rising to the top of the pan pass into the streams of coldWater which cause the same to condense and this, water and condensedvapor pass out through the outlet 17 The trough 16 is of greater widththan the water chamber 19 as will be understood from Fig. 3 preventingpossibility of any water passing into the pan proper and the vapor mayrise and pass into the streams of water from both sides of the troughpermitting a greater volume of vapor per unit of time to come in contactwith the cold condensing water than is possible with formerconstructions. lVith the former types of vacuum pans having theconstricted upper end, a greater expenditure of effort was required ascompared with the type here shown to maintain the vacuum due to thenecessity of increasing the velocity of the flow of vapor at therestricted end and the tendency of such restricted end to increase thepressure in the pan. Vith the cylindrical pan of uniform diameter ashere shown, the desired degree of vacuum is more readily maintained andwithout variation in pressure. Also an increased rapidity of evaporationis secured, due to the method of applying the heat. As heretofore statedthe vapors may move more slowly than with the former type and still agreater rapidity of condensation is secured due to the area of the vaporpermitted to contact with the cold streams of water. The structure ofthe condenser and the positioning of it diametrically across the shellat the upper end permit the vapor to rise to contact with the condensingwater on both sides of the condenser for the full length thereof. Thisequally distributes the steam or vapor relative to the water streams andit is possible to condense the vapor with a less volume of water therebyeffecting a material saving in the cost of operation. By forming the panof uniform diameter throughout its height the velocity of the vapor isnot increased as it passes to the condenser and therefore the pressureduring evaporation is not increased.

\Vith the previous constructed types of vacuum pans heretofore mentionedand with the type of pan shown in the U. S. patent to C. T. Rogers, No.795,650 there is a tendency for the non-condensible vapors to accumulatein the top of the pan and thus prevent the condensible vapors properlycoming in contact with the condensing water and passing from the pan. Inmy improved form of water chamber I preferably form the bottom 20 in aslightly curved form as shown in Fig. 8 On the outer longitudinal sidesof the water chamber 1 provide a series of rows of apertures quiteclosely spaced and between these two marginal rows other rows ofapertures are provided in which both the rows and apertures are spacedfarther apart than is the case with the marginal rows. The vapors, inpassing up in the direction of the arrows shown in Fig. 8 over thetrough, pass into the streams of the condensing water. It will be notedthat there is a large area of water with which the vapors may come incontact in passing into the trough. The arcuate form is preferred tocause a distribution in the water chamber 19 to each of the longitudinalsides to insure the maximum flow at these points but water is dischargedalso at the center of the water chamber to prevent an accumulation ofnoncondensible gases between the marginal rows of streams of water.These central streams drive any noncondensible gases downward into thetrough to discharge from the pan. If the streams were arranged to fallin a circle or some similar form within which there is an area that maybecome filled with noncondensible gases, the presence of such gaseswithin the outer wall of the water streams prevents movement of thecondensible vapors into the streams and the noncondensible gases in suchprevious gases accumulate until there is sutlicient pressure to forcethe same over and out through the outlet. This of course is practicallyinstantaneous and is very detrimental in that the vacuum is increasedand the heat leaves the fluid so rapidly as to cause it to foam, in factto rise to the top of the pan and pass out through the outlet afterwhich period such previous type of pan may again function properly for atime until the noncondensible gases have again accumulated. By myimproved construction in which the pan is of uniform diameter to a pointlevel with the point of entrance of the vapor streams there is noincreased velocity of the vapors in the upper part of the pan as is thecase with the constricted type heretofore mentioned but in fact a slowermovement of vapor is secured although greater in volume. By ar rangingthe condenser extending diametrically across the pan with flow of vaporto both sides of the body of the streams the condensation is rapid dueto the area of vapor in contact with the water.

These features coupled with the increased efficiency of the heatingapparatus result in a more highly efficient apparatus than hasheretofore been known in this art and the cost of condensing fluids isreduced while also the cost of manufacture of the pan as compared withthat of the heretofore used restricted type is also materially reduced.

What I claim and desire to secure by Letters Patent of the United Statesis 1. A vacuum pan, a shell of substantially uniform diameter throughoutits height, a

condenser within the shell at the top, said condenser consisting of anopen trough shaped member near the top extending diametricallythereacross and having an outlet to the exterior of the shell, a waterchamber thereabove less in width than the trough, the bottom wallthereof having a series of rows of apertures throughout its length andwidth for discharging the water into the trough, the marginal rows ofthe apertures being greater in number than the rows dischargingcentrally over the trough.

2. In a vacuum pan, a shell of substantially uniform diameter throughoutits height, a cover plate therefor, a water chamber on the under side ofthe cover plate, the lower bottom wall of which is substantially inalignment with the end of the shell, and the bottom wall beingperforated practically throughout its length and width providingapertures through which water may be discharged, the chamber beingnarrow in width extending diametrically across the top of the shell, atrough shaped member below the said top of the shell and beneath thewater chamber, the said trough being greater in width than the waterchamber and the arrangement permitting vapors to flow upwardly andinwardly over the trough to contact with the water streams, and anoutlet for the trough leading to the exterior of the shell.

3. In a vacuum pan, a shell of substantially uniform diameter throughoutits height, condensing means in the upper part of the shell, saidcondensing means comprising a trough shaped member of comparativelynarrow width extending diametrically across the shell and provided withan outlet to the exterior at one end of the trough, a water chamberabove the trough the bottom of which is less in width than the troughand higher at the center than at the marginal edges, the said bottomthroughout its length and Width being provided with a series ofapertures extending longitudinally thereof at each edge and other rowsof apertures between the said marginal rows spaced a greater distanceapart than the marginal rows.

4:. In a vacuum pan, a shell of substantially uniform diameterthroughout its height, a condenser near the top consisting of an opentrough shaped member extending diametrically across the said top andhaving an outlet to the exterior of the shell, means positioned abovethe trough adapted to discharge water in fine streams throughout an areaapproximately equal to the length of the trough and less than the widththereof providing for a fiow of gases into the trough from both sides,and preventing an accumulation of gases in the shell above the trough.

In testimony whereof, I sign this specification.

CHARLES E. ROGERS.

